Basically "fever-all" is a mushy capsule full of tylenol (Acetaminophen) that you have to stick in your kid's butt about 2" and leave there; then put on a diaper.
If he's got a high fever, run to a pharmacy and give it to him asap, it works in like 20-30 minutes. You need the 120mg:
http://www.feverall.com/retail.html
Only one every 4-6 hours. Follow the dosing, do not go over the rcommended.
IMO low grade fevers from 99-101.9 can be ok but need to be watched, when my kid goes over 102 I like to act fast, he can get to 104 quick and that's not healthy.